kieffer



" PATENTED FEB. 16, 1904.

v J. L, KIBPFER. STITCH FORMING MECHANISM FOR SHOE SEWING monnms.

urmomron FILED JULY 14, 1902.-

4 EHEETS-SHEET 1 HO MGDEL.

CZVSQ/J/ Inventor,

V Attorneys i'HE cams PETERS co, Pnurau'mu. WASHINGION. 0. 12V

PATENTED FEB. 16, 1904.

J. LLKIEFFER. STITCH FORMING MECHANISM FOR SHOE SEWING MACHINES.

APPLICATION FILED JULY 14. 1902.

4 sums-sum 2; 7

Inventor,

(Jase 23 Kieffiaz:

mh n w NO MODEL.

Witn's'ses:

Attorneys No. 752,398. PATENTED FEB. 1-6, 1904. f

- J. L. KIEEPER.

STITCH FORMING MECHANISM FOR SHOE SEWING MACHINES.

APYLIOATIDH P ILED JULY 14 1902.

v 4 SHEETS-SHEET 3Q N0 MODEL.

F 05' ep/ /zffieff inventor,

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Attorneys mus PETERS cu, vnoroumm. wAsnmdtQn n c PATENTEDIFEB. 1-6,1904.

J. L. KIE ER; v i STITCH FORMING MECHANISM FOR SHOE SEWINGMAGHINBSKPPLIGATIDN FILED JULY 14. 1902.

4 SHEETS-BHBET 4.

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Witnesses 0567M lalll sj yfr |nvent0fl Attorneys PETERS co PKDTULD'HOY.wnsumsrout n. c

Patented February 16, 19 04: I

I UN STATES PATENT OFFICE.

- ing in the city and district of Montreal, Prov- I shoe andleathermachinery, because of-the' formed in a given space-of time.

JOSEPH Louis KI-EFFER, or MONTREAL, CANADA.-

STITCH-FORMING MECHANISM FOR SHOE-:SEWING MACHINES.

SPECIFICATION formingrpart of Letters Patent No. 752,398, dated February16, 1904;.

Application and July 14, 19 02. 1 stab No. 115,589. (No model.)

To all whom, it may concern." I

Be it known that I, Josnru Loms KIEFFER, a subject of the King of GreatBritain, residince of Quebec, Canada, have invented certain new anduseful Improvements in Stitch-Forming Mechanism for Shoe-SewingMachines; l and I do hereby declare thatthe following is i a full,clear, and exact description of the inyehtion, such aswill enable othersskilled in the art to which it appertains to make and use fibers ofthread have to undergo a rubbing the same.

My invention relates to improved stitch-- forming mechanism adapted forshoe and leather. sewing machinery of that class known as the.outsole-stitcher, and especially that type forming the stitchknown. as,a lock stitch,,wherein an upper or bobbin thread and a lower or machinethread are employed and interlocked one with the other. 7 The object ofmy present invention'is to produce an improved stitch-forming-mechanismof the revolving-hook class which shall em- .body all the advantages ofthe oscillating hook described inmy Patent No. 719., 980, dated Feb- 1ruary 3, 1903, while at the same time embody- I ing the additionaladvantages which are inherent in the revolving-hook over. theoscillating-hook type of apparatus. The particular object had ventionherein described. is to greatly increase the capacity of the machine bydoubling or a tripling the number of stitches which may be Acomparatively slow speed is necessarily inherent .in

Weight and momentum of the movingparts,

a much greater rate'of speed than an oscillating hook, because themotion is, comparatively speaking, continuous, whereas that of: the: os-

cillating hook requires to be reversed twice during the formation ofeach stitch. The inertia of the hook puts alimit,depending. on thestrength and resistance of the materials, upon the rate of speed atwhich the hook travels, and hence the revolving hook can be run in Viewin the in- I at a much greater speed than the oscillating hook. V y

A further object of this invention is. to improve the motionof-the partsin carrying the thread over the bobbin, by. which friction between; thebobbin-case and the box in which it lies is, as far as possible,eliminated. That this is avery important feature ofshoe-sewing machinesis a matter of experience with all those who have had occasion to testthem,

because the number of times which the same action in being drawn overthe bobbin is great in proportion to the amount of threadneces- I saryin order to form the drawn-out threadloop as compared with the finishedstitch, and

this makes the question of friction byabrasion of the thread during theformation of the stitch an extremely important one. The difference isseen to a marked degree in comparing several of the differentmachinesnow on the market, because in some there is so great 'an abrasion of thethread (although thisis. not noticeable to the eye or to ordinaryinspection) that the stitch cannot be drawn up tight without breakingthe thread, and therefore a loose and inferior quality of work is thenecessary result.

In my present invention I have so arranged the parts as to practicallyeliminate altogether the rubbing or bruising of thethreadbetween thebobbin-caseand the bracket which supports the same, except at a singlepointduring the formation of-a stitch; l 7

my present inven It is a further ob'ect of tion to. eliminate altogethera veryimportant but hitherto. apparently unnoticed source of abrasion ofthe thread, which lies in the manner' in which the thread is removedfrom the barbed needle, which brings. up thethreadloop through the work.The inventions heretofore produced for delivering the thread from theneedle and carrying it around the bobbin havenot had sufficient regardfor the sharp edge of the barb of the needle whereby every:

time the thread was removed it was caused to rub or scrape over saidbarbed edge, and

thereby become abraded, and inasmuch as the same fibers were thus cutand abraded over nose, one limb of which is adapted to receive thethread, while the otherthat is to say, the outer limbis simply a guideto direct one lap of the thread-loop over the bobbin.v

These two limbs of the hook take the place,

respectively, of the recurved nose and of the body of the oscillatinghook described in my former applications. The hook thus formed isattached to a rotating disk at the rear of the bobbin-case and in thecenter thereof, and on the edge of this disk, at a point just in advanceof the nose of the hook, is formed a forwardly-projecting rim or flangewhich is adapted to serve partly as a shield to cover the point of theneedle during the drawing up of the thread-loop by the take-up mechanismand partly to operate the bobbin-case to throw it from one side to theother in connection with the means for preventing the friction of thethread between the bobbin-case and bobbin-bracket, as will be presentlyreferred to.

My invention also comprises a longitudinal or arcuate groove formed inthe rear side of the hook, into which the needle is adapted to passduring the delivering of thethread-loop therefrom, combined with acertain cam movement whereby the hook is brought to a stop while theneedle is passing into said groove and caused to start again only afterthe barb of the needle has completely entered the groove and thethreadhas been completely delivered therefrom.

My invention further consists in the particular form of the insidesurface of the bobbin-bracket, which is not, as heretofore was the case,a perfect surface of revolution fitting thebobbin-case all round, but iscut away all around except at three points equally or otherwise spacedaround the inner periphery of the bracket, so as to support thebobbin-case from these three points only, but rather from two of thesepoints only, the bobbin being arranged to rest on the bottom or lower ofthe three bosses or knobs thus formed and slightly also against one ofthe others, whereby the thread in passing over the bobbin cannot rubbetween the two surfaces at any more than two points from beginning toend. With this conformation, moreover, is conjoined a finger or tripextending inwardly from the threadhook or the disk by which it iscarried, so as to strike against the bobbin and push it over from oneside to the other in advance of the thread, and thereby just before thethread passes between the bobbin case and bracket at a point of contactof the two they are caused to be separated, so that the thread passesthrough without friction, and the same operation is performed at theother side of the center. This operation will be understood more clearlyfrom the accompanying drawings and description.

My invention further consists in the peculiar construction andcombination of parts, which will be hereinafter described, and moreparticularly pointed out in the claims.

As many of the features of my present invention can be equally wellapplied to the oscillating thread-hook formerly invented by me, I haveillustrated the oscillating threadhook in conjunction with the rotatinghook to show the application of these features.

The elements and construction of my invention in its most improved formand modifications are shown in the accompanying drawings, in whichFigure 1 1s a side elevatlon of the new form of revolving thread-hook inthe act of formthread-loop is being delivered from the needle.

Fig. 3 shows the third step in the formation of the stitch,in which thethread-loop is being car'- ried over the bobbin. Fig. 4 is a similarview to Figs. 1, 2, and 3, but showing the'fourth stepin' the formationof a stitch, in which the thread is being cast off and the stitch drawnup by the take' up mechanism. Fig. 5 is a similar view showing the laststep in the formation of the stitch. Fig. 6 is a central verticaltransverse section through the stitch-forming mechanism, the parts beingin the position shown in Fig. 1. Fig. 7 is a similar view to Fig. 6, theparts being in the position shown in Fig. 2. Fig. 8 is a similar viewshowing the parts in the same position as in Fig. 4:. Fig. 9 is aperspective view of the thread-hook from the front side. Fig. 10 is asimilar view of the hook from the rear side. Fig. 11 is a perspectiveView of an oscillating thread-hook having my invention applied thereto.Fig. 12 is a front elevation,.on an enlarged scale, of a modified formofistitch mechanism, showing more distinctly the method of operating thebobbin-case. Fig. 18 is a similar view of the same device as in Fig. 11,illustrating a subsequent step in the formation of a stitch.

Fig. 14 is a perspective view of the bobbinbracket from the rear side.Fig. 15 is a side elevation of parts of a machine embodying myimprovements in situ, the rotating hook being shown in central sectionto illustrate the timing of the relative movements of the thread-hookand needle; and Fig. 16 is a velocity-diagram of the movements of thehook. The same numerals of reference denote like parts in all thefigures of the drawings.

In the drawings, designates a block, as of metal, which is herein calledthe threadhook block, because it serves to support the thread-hook andthe other operative parts of the stitch-forming mechanism. This block issupposed to besecured on thework-head of the machine and is not fullyshown herein, because its form is a matter of indifierence' to thepresent invention, although that shown in my previous application,Serial No. 105,493, filed May 1, 1902, is an appropriate form. Thisblock 15 is formed with a shallow cylindrical recess 16 in its frontface, in which operates the revolving hook 17, which is formed as anarcuate extension of the thread-hook disk 18, mounted to rotate upon aspindle 19, which passes through the "rear side of the block 15. Thethread-hook disk 18 forms the secured by bolts 21 to the block 15, andhaving a depending annular portion 22, which serves to loosely confinethe bobbin-case 23, this case being, as shown in Figs. 6, 7, and

and then against the other.

8, of a double-conical form having a surface of revolution with a sharpelbow 24, which is. adapted to divide the thread-loop. The

front face of the bobbin-case 23 is left open by means of the centralaperture 25, formed in the bobbin-bracket. bobbin-bracket is ofroughly-conical form, corresponding to the exterior surface of thebobbin-case; but it has not a surface of revolution, because, as shown,it has three irregu- 'larly-spaced bosses thereon, (designated, re-

spectively, '27, 28, and 29.) It is on these three 'bos'ses that thebobbin-case 23 rests; but it;

The inner side 26 of this does'notrest on all three at once, because itis loose within the box and has a considerable amount of play and iscaused to be thrown from side to side by the motion of the threadhook ina manner which Will be described. 'The lowermost boss 27 forms aconstant resting-point for the bobbin-case; but the other twobosses 28and 29 are merely buffers which that the bobbin-case rests first-againstone The bosses 28 and 29 are not at equal distances from the bottom boss27; but, as shown, the boss 28 on the right or rising side of thethread-hook is about ninety degrees from the boss 27, whereas the otherboss, 29, on the left or descending side of the thread-hook is about onehundred and sixty degrees from the boss 27. i The ring 22 of thebobbin-bracket has also a notch 30 in the center of the boss 27, whichcoacts with a depending lip 31, formed on the bobbin-case, to preventthe same from rotating slipped easily thereover and to pass out frombetween the bobbin case and bracket.

Before describing further the mode of operation of the thread-hook inconnection with the bosses 27, '28, and 29 and the bobbin-I case I willdescribe the general form and mode of operation of my improved revolvingthread-hook, which is shown in Figs. 1 to 8, inclusive, and in enlargedperspective view in Figs. 9 and. 10. The disk 18 has at the centerthereof a bored-hub 32, through which passes the shaft 19, whichprojects at the rear ofthe block 15, and has also mounted thereon backof the hub 32 a screw-gear pinion 33, having a long bearing-sleeve 34projecting into the bearing-block 35, secured on the work-head of themachine, and the several parts are clamped up together on the shaft 19by means of lock nuts 86 passing over the screw-threaded end 37 of theshaft. In order to tighten the lock-nuts 36 in place, I preferablyrecess the end of the shaft 19 and split thesame laterally, as by cuts37, and insert in the recessed end a wedge-screw 37 The screw-gear andthread-hook disk are also prefably-keyedtogether in proper relativeposition by any suitable means, such as interlocking lugs 38. v

WVith the screw-gear pinion 33 coacts a similarly-formed pinion 39,whose shaft 10 is at right angles to the shaft 19, but does notintersect the same, and the shaft 41-0 is kept in continuous butirregular rotation by means of suitable 'cam mechanism, 'so as to givethe proper motions, which will be hereinafter described, to thethread-hook 17 in its rotation.

The thread-hook 17 is formed, as shown, with a double forwardly-directednose having two limbs, (designated, respectively, 11 and ea) the upperof which, 11, is the effective or operative limb, which serves to removethe thread-loop from. the needle and carry it around'the bobbin, whilethe lower limb, 12,

of the nose is somewhat shorter than the limb 11 and has its forward enddirected somewhat backwardly, so that it is inserted behind the rear lapof the thread-loop and serves to push it out and cause it pass throughthe bight or slot -13 between the two limbs of the hook.

The book 17, behind the junction of the two limbs 11 and 42, has areduced neck 44:, which serves to permit the easy passage of the threadover the bobbin in a manner which will be which form a part of myinvention.

of the cam motions given to the hook and needle, respectively, in such amanner as to leave the thread-loop clear of the barb of the needlewithout causing abrasion on the sharp edge of the barb, and theparticular motions by izvhich this result is produced will be describedater.

The front side of the thread-hook disk 18 is dished out to form ashallow recess 47, having conical sides and corresponding to the shapeof the bobbin-case, so'as to allow the same to sit loose therein; but itonly touches the bobbin-case normally at one pointthat is to say, thepoint designated herein, 48-which is in the shape of a slightlyeccentric heel formed just in advance of the point of the upper limb 41of the hook. The object of this is to push the bobbin-case at all timesinto a position.

farthest from the point of the hook, and with it coact the three bosses27, 28, and 29, so as to push the bobbin-case over first to the left andthen to the right as the hook revolves. In advance of the heel 48 isformed an outwardlyprojecting rim 49, which forms a shield or guard forthe barb of the needle during the drawing up of the thread-loop afterits passage around the bobbin and to prevent the loop from becomingentangled with the needle.

In Fig. 15 I have shown in side elevation and partly in section the hookand needle, together with their cams and cam-levers, in order toillustrate the interaction of theparts At 61 is shown the main shaft ofa shoe-sewing machine of any suitable type, on which shaft is keyed acam-block 62 by means of the keyv 63. This cam-block has a cam-groove oneach side, (designated 64 65,) in which work the rollers 66 67 of a pairof interacting cam-levers 68 69, which are pivoted on pins 70 71, theformer of these levers being arranged to occupy a generally verticalposition and the latter a horizontal. On the end of the shaft 40 isformed a crank 72, having a pin 7 3, on which is pivoted the end of alink 74, which is joined by a pivot-pin at an intermediate point thereofto the end of the lever 69, while its upper end is connected by a link76, pivoted at 77 to the upper end of the lever 68. The formation of thecam-grooves 64 65 is such as to cause the crank 72 to rotatecontinuously in one direction, being counter-- clockwise, as shown bythe arrow in Fig. 15, the shaft 61 also rotating in a counter-clockwisedirection, and not only this, but the formation of the cam-grooves 64 65is such as to impart a variable rotative speed to the crank- 72, andhence to the thread-hook, the variaat the back of the machine (hereinshown as coaxial with the pin 71) and is operated by a roller 83,mounted on it at an intermediate point and running in a cam-groove 84 inthe side of another camblock behind the camblock 62, as is usual in suchmachines. At 85 is shown a needle-guide which embraces the stem of theneedle and at 86 the table on which the work rests, these beingcustomary parts of the mechanism and forming no part of the presentinvention.

The mode of operation of' my improved rotating hook may be described asfollows: The bobbin-case, mounted in its box, rests loosely against thelower boss 27 of the bracket, in which position it is slightly below theaxis of the revolving hook. Supposing now the thread-hook (which in thepresent drawings rotates in a counter-clockwise direction, as shown bythe arrows) to be in the position shown in Fig. 1, in which the needlehas reached the top of its stroke, carryinga threadloop 50 through thework 51. The point 41 of the hook is so positioned as to enter betweenthe two laps of this loop in the manner shown in Fig. 1, and as themotion of the hook proceeds the lower limb 42 of the hook passes beneathand behind both laps and causes the rear lap to be inserted into thebight 43. When the hook has reached the position shown in Fig. 2, itsmotion ceases for an instant, and during this period of rest the needlemoves forwardly and enters the groove 45, having previous to that timeremained outside this groove. The advance of the needle is sufficient toentirely deliver the thread-loop therefrom, leaving it cast off the barbof the needle onto the limb 41 of the hook, (see Figs. 7 and 15,) andafter this cast-ofl movement has been accomplished, which occupies butan instant, the hook moves forward again and carries the loop around thebobbin in the manner indicated in Fig. 3, the two laps of the looppassing, respectively, on opposite sides of the bobbin, which is enabledto take place by means of the reduced neck 44. It will be observed,further, that the ring 26 of the bobbin-bracket has on its inner rightside adjacent to the boss 27 a slight nick or recess 51, which furtherenables one lap of the threadloop to pass around the bobbin withoutexcessive friction. Further,.it will be noticed that when thethread-hook reaches the position shown in Fig. 2 and after that the heel48 thereof will strike against the bobbin-case and throw it over, so asto cause it to rest against the boss 29, as indicated, and in this casethe thread can pass between the boss 28 and the bobbin-case withouttouching the former. When, however, the hook reaches the position shownin Fig. 3, the heel 48 now strikes the bobbin-case from the other sideand throws it back so as to rest against the boss 28, and the boss 28having been now passed the thread can likewise pass the boss except at asingle point-that is to say, at the 1 lower boss'27, on which thebobbin-case is supported. i

In Fig. 16 is given a velocity diagram to illustrate the velocity of thethread-hook at each point of its revolution. The thread-hook is shown,at the center of the diagram in its zero position, thezero-point beingtaken on a line 87, extending vertically downward from the central point0. The velocity of the thread-hook at any point of its revolution isindicated by that portion of a radius-vector included between the circle88 and the curve 89; The numerals, ranging from 1 to 20 on the outsideof the circle 88, represent equal angles passed through by thethread-hook, the corresponding'abscissas representing velocity beingdrawn in each case. On the inside of the circle is a second series ofnumerals 1 to 20, which represent the positions of the hook at equalintervals of time. The positions of these angles are taken for a pointon the hook lying in the line 87 in the zero position.

It will be seen from the diagram that the motion of the hook startingfrom the zero position increases uniformly up to the position 7 and fromthere decreasesagain to the position 14, this being during the operationof carrying the thread over the bobbin after the same has been releasedfrom the needle, and which, therefore occupies but about fourtwentiethsof the time of a complete cycle. At theposition 14 the hookbecomesnearly or quite stationary, giving time for the successiveoperationof the take-up, the feed mechism, the needle, and the looper,this occupying.

about twelve-twentieths of the timeof a complete cycle, and at the endof this time the thread-hook again advances as rapidly as possible toits zero position, where it comes to a stop long enough to allow theneedle 59420 move forward into the groove 45, as already explained, andcast off the thread-loop drawn up by it during the time interval4to 16,whereupon another cycle is commenced. It will be seen that at thezero-point a small loop is 1 formed in the curve 89 within the circle88,

indicating that a small backward motion may be given to the hook, iffound desirable, during the period 18 to 20, which will absolutelysecure that the thread-loop is pressed against the stem of the needleduring the time that the latter is entering the groove 45, or tocounteract the tendency of the thread-hook to a slight torsional bendingdue to the sudden checking of its forward momentum, By

following out thecam-grooves 64, 65, and 84 it will be seen that theyare so arranged as to give the thread-hook the motion illustrated inFig. 16, and also during the interval 4' to 16 to advance the needle andagain retract it to its highest position, and then to slightly againadvance it in the interval 18 tofZO. The

thread-hook is shown as having a very slow advance movement during theperiod 14 to 17, it being limited in its advance to the position 17 upto the end of the time interval 16 order to give time for the needle toreturn to its original position, carryingthe thread-loop before thepoint of the thread-hook crosses the needle.

It will be understood that the motion of the thread-hook thus describedis practically continuous and nearly uniform, except at two pointsthatis to say, in the position shown in Figs. 4 and 5 and in that shown inFig. 2.. In the former of these it stops or is retarded during a shortinterval to give time for the thread to be taken up and also for theadvance of the needlethrough the work to form an additional thread-loop.In the second position it stops to enable the loop carried by the needleto be cast off without any abrasion of the thread against the barb. Thelatter is.

an important featureof this invention inasmuch as all previous devicesfor delivering the thread-loop from the needle have entirely overlookedthis point or have failed to solve it satisfactorily, so that the threadwas carried off the barb of the needle so as to scrape or rub thereon,and thereby cause the fibers of the thread to become broken. Theinstantaneous stoppages of the thread-hook, however, are comparativelyunimportant when considered in connection with the oscillating book,because the latter had not only to be stopped at a certain point in itsmotion, but it had additionally to have its motion reversed twice in asingle cycle, and the reversal of so heavy a part necessarily requirestime. In

consequence I find that I can operate my pres- 'ent revolving hook at amuch greater speed than the oscillating book, so as to form from six toeight hundred stitches per minute. As,

as described in my former application, consists of a forwardly-directedpoint 53, a recurved nose 54 behind the point, and a grooved tail-shield55. A groove 5'6 is also formed in the rear face of the hook, into whicha needle passes in the operation of delivering the thread from theneedle. In this case just behind the nose 54 is provided a triangularhump 57 cient distance below the axis of the threadhook to enable thehump 57 to pass over thetop thereof. The operation of this form of thedevice is precisely similar to that first described, because the hump 57takes the place of the heel 48 and serves the same function of tippingover the bobbins lightly in advance of the hook.

While I have shown in the accompanying, drawings the preferred form ofmy invention, it will be understood that I do not limit myself to theprecise form shown, for many of the details may be changed in form orposition without affecting the operativeness or utility of my invention,and I therefore reserve the right to make all such modifications as areincludedwithin the scope of the following claims or of mechanicalequivalents to the structures set forth.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a stitch-forming mechanism for shoesewing machines, a thread-hookcomprising a forked nose, one limb of which is adapted to enter anddeliver the thread-loop from the needle, and the other to guide the rearlap of theloop into the bight of the hook.

2. A stitch forming mechanism for shoesewing machines comprising abarbed needle adapted to enter the work and bring up a thread-looptherethrough, and a continuouslyrotating thread-hook having aforwardly-directed forked nose, the inner limb ,of which is longer thanthe outer and is adapted to enter the thread-loop and deliver it fromthe needle, andthe outer limb of which is adapted to push forward bothlaps of the thread-loop and cause the rear lap to fall into the bight ofthe hook.

3. A stitch forming mechanism for shoesewing machines comprising abarbed needle adapted to enter the work and bring up a thread-looptherethrough, and a continuouslyrotating thread-hook having aforwardly-directed forked nose, the inner limb of which is longer thanthe outer and is adapted to enter the thread-loop and deliver it fromthe needle, and the outer limb of which is adapted to push forward bothlaps of the thread-loop and cause the rear lap to fall into the bight ofthe hook, said upper limb of the hook having a groove in its inner faceinto which the needle is adapted to pass.

4. A stitch forming mechanism for shoein its rear face into which theneedle is adapted to pass, means for rotating the hook and stopping thesame at a point wherethegroove is opposite the needle, means forthereafter causing the needle to enter the groove while the hook isstationary and leave the thread on the hook, and means for thereaftercontinuing the rotation of the hook, substantially as described. v

5. A stitch-forming mechanism for shoesewing machines comprising abarbed needle adapted to enter the work and bring a threadlooptherethrough, a rotating disk forming the rear of a bobbinbox, abobbin-bracket closing the front of said box, a bobbin loosely mountedin said box, a thread-hook having a forwardly directed forked noseextending from the periphery of said disk, .the upper limb of said nosebeing adapted to enter the thread-loop and deliver it from the needle,and the lower limb being adapted to push back the rear lap of the loop,and a shield adapted to cover the point of the needle subsequent to thecasting off of the thread-loop and during its drawing up by the take-upmotion.

6. A stitch-forming mechanism for shoe-- sewing machines comprising abarbed needle adapted to enter the work and bring a threadlooptherethrough, a rotating disk forming the rear of a bobbin-box, abobbin-bracket closing the front of said box, a bobbin loosely mountedin said box, a thread-hook having a forwardly' directed forked noseextending from the periphery of said disk, the upper limb of said nosebeing adapted to enter the thread-loop and deliver it from the needle,and the lower limb beingadapted to push back the rear lap of the loop,and a shield adapted to cover the point of the needle subsequent to thecasting off of the thread-loop and during its drawing u by the take-upmotion, the upper limb of said thread-hook having a groove in its rearface into which the needle is adapted to enter and to leave thethread-loop on the hook.

7. A stitch-forming mechanism for shoesewing machines comprising abarbed needle adapted to enter the work and bring up a thread looptherethrough, a rotating disk forming the rear of a bobbin-box, abobbinbracket closing the front of said box, a bobbin loosely mounted insaid box, a threadhook having a forwardly-directed forked nose extendingfrom the periphery of said disk,

the upper limb of said nose being adapted to enter the thread-loop anddeliver it from the needle, and the lower limb being adapted to pushback the rear lap of the loop, a shield adapted to cover the point ofthe needle subsequent to the casting oif ofthe thread-loop and duringits drawing up by the take-up motion, the upper limb of said thread-hookhaving a groove in its rear face into which the needle'is adapted toenter and to leave the thread-loop on the hook, means for rotating 7 thehook continuously in one direction, means 8. Inastitch-formingmechanism,in combination, a bobbin -case, a circularly-moving member adapted tocarry a thread thereover and a bobbin-bracket supporting the case, theadjacent surfaces of the bobbin case and bracket being so conformed toeach other. as to touch in only three possible points, so situated withrespect to each other that each point lies on the opposite side of adiameter from the other two. 7

9. In a stitch-forming mechanism for shoesewing machines, in combinationwith a bobbin-case, a bobbin-box, and the hook, of a bob bin-brackethaving a ring forming the cover of the bobbin-box, said ring being cutaway on its inner surface to form three bosses on the lower one of whichthe bobbin-case is adapted to rest, and against the upper two of whichthe bobbin-case is adapted to rest alternately. I

10. In a stitch-forming mechanism,the combination of a bobbinbox, abobbin-case loosely mounted therein, the hook and a bobbinbracketforming the cover of said box and having three raised points around itsperiphery,

upon one of which the bobbin-case is adapted to be supported, andagainst one of the other two of which the bobbin-case is adapted toalternately rest.

l 1. In a stitch-forming mechanism,the combination of a bobbin box, abobbin-case loosely mounted therein, a bobbin bracket forming. the coverof said box and having three raised points around its periphery, uponone of which the bobbin-case is adapted to be supported, and against oneof the other two of which the bobbin-case is adapted to alternatelyrest, and means for throwing the bobbin-case first to one side and thento the other in advance of the passage of the thread between said raisedpoints and the bobbin-case.

12. A stitch-forming mechanism for shoesewing machines comprising abarbed needle adapted to enter the work and bring a threadlooptherethrough, a thread-hook block having a shallow cylindrical groovetherein form ing the bobbin-box, a thread-hook adapted to move aroundthe periphery ,of said box, a

bracket formingrthe coverof said box, a circular bobbin-case looselymounted 111 said box, a

recess therein forming a bobbin-box, a spindle passing through the rearof said block in the center of said recess, meansfor unevenly r0 tatingsaid sp1ndle,'a disk mounted on the foran arcuate thread-hook mounted onsaid disk and having aforWardly-directed forked nose, the inner limb ofsaid nose being longer than the outer, a bobbin-bracket having a ringclosing the front of said bobbin-box, a bobbincase loosely mounted insaid box, means for preventing said bobbin-case'from rotation, and ashield adapted to cover the barbed needle during the drawing up of thethread-loop.

14. A stitch-forming mechanism for shoe and leather sewing machinerycomprising a ward end of ,said spindle within said recess and formingthe rearface of said bobbin-box,

an arcuate thread-hook mounted on said disk and having aforwardly-directed forked nose, the inner limb of said nose being longerthan the outer, a bobbin-bracket having a ring closing the front of saidbobbin-box, a bobbincase loosely mounted in said box, means forpreventing said bobbin-case from rotation,

, ward end of said spindle within said recess and forming the rear faceof said bobbin-box,

IIO

said bobbin-bracket having a series of three 15. A stitch-formingmechanism for shoe and leather sewing machinery comprising a thread-hookblock having a shallow cylindrical recess therein forming a bobbin-box,a spindle passing through the rear of said block in the center of saidrecess, means for unevenly rotating said spindle, a disk mounted on theforward end of said spindle within said recess and forming the rear faceof said bobbin-box, an arcuate thread-hook mounted on said disk andhaving a forwardly-directed forked nose, the inner limb of said nosebeing longer than the outer, a bobbin-bracket having a ring closing thefront of said bobbin-box, a bobbincase loosely mounted in said box,means for preventing said bobbin-case from rotation, said bobbin-brackethaving a series of three raised points or bosses on its inner peripherywhich serve as supports and stops for said bobbin-case, and an eccentricheel or hump carried by said thread-hook and adapted to strike againstthe side of the bobbin-case for throwing the bobbin-case over to theside farthest from the nose, whereby the thread is permitted to passover the bobbin-case without friction between it and its supports,substantially as described.

16. A stitch-forming mechanism for shoesewing machines comprising athread-hook block having a shallow cylindrical recess therein,-a shaftpassing through the rear of the block in the center of the recess, meansfor unevenly rotating said shaft continuously in one direction, athread-hook disk secured on the forward end of said shaft within saidrecess and having a dished front face adapted to conform with the shapeof the bobbin-case and to form the back of the bobbin-box, a bracketcoacting with said disk to form the cover of said bobbin-box and havinga ring adapted to surround the bobbin-case, a bobbin-case looselymounted between said disk and ring, a series of three raised pointsrespectively at the bottom and on opposite sides of the inner peripheryof said ring on the first of which the bobbin-case is supported andagainst one of the other two of which the bobbin-case rests alternately,a thread-hook having a forwardly-directed nose adapted to enter thethread-loop and deliver it from the needle, a barbed needle coactingwith said thread-hook, and an eccentric heel or hump in advance of saidthread-hook, whereby the bobbin-case is thrown over in advance of thepassage of the thread thereover to cause it to" pass between it and itssupports frictionlessly.

17. A'stitch-forming mechanism for shoesewing machines comprising athread-hook block having a shallow cylindrical recess therein, a shaftpassing through the rear of the block in the center of the recess, meansfor unevenly rotating said shaft continuously in one direction, athread-hook disk secured on the forward end of said shaft within saidrecess and having a dished front face adapted to conform with the shapeof the bobbin-case and to form the back of the bobbin-box, a bracketcoacting with said disk to form the cover of said bobbin-box and havinga ring adapted to surround the bobbin-case, a bobbin-case looselymounted between said disk and ring, a series of three raised pointsrespectively at the bottom and on opposite sides of the inner peripheryof said ring on the first of which the bobbin case is supported andagainst one of the other two of which the bobbin-case rests alternately,a thread-hook having a forkedforwardly-directed nose, the inner limb ofwhich is longer than the upper and provided with a groove in its rearface, a barbed needle adapted to enter the work and bring a thread-looptherethrough and to coact with said hook, means for advancing said hookto a point opposite said needle and then momentarily stopping said hook,means for subsequently advancing the needle into said groove asuflicient distance to clear the loop from the barb thereof and leave iton the hook, means for thereafter advancing the threadhook and carryingthe loop over the bobbin, and an eccentric heel or hump adapted tostrike againstsaid bobbin-case slightly in advance of the hook and throwit over so as to permit the thread-loop to pass between the bobbin-caseand its supports frictionlessly.

In witness whereof I have hereunto set my hand in the presence of twowitnesses.

JOSEPH LOUIS KIEFFER.

Witnesses:

J. A. MARION, T. MYNARD.

